Methods and systems for the efficient acquisition, conversion, and display of pathology images

ABSTRACT

A method for viewing pathology images in a web browser is provided. The method includes obtaining a pathology image in a first format, converting the pathology image into a pyramid representation file comprising images grouped into a plurality of levels, wherein the images in the different plurality of levels correspond to portions of the pathology image at a same or different degrees of resolution, and wherein the images are in the first format, storing the pyramid representation file in the first memory, receiving a request from a user to view the pathology image at a specified resolution, loading one or more images from at least one of the plurality of levels corresponding to the specified resolution, wherein the one or more images are in the first format and wherein the one or more images are loaded into a web browser coupled with the first memory, converting the images into a second format such that the images&#39; degrees of resolution are maintained, and storing the images in the second format in a second memory.

CROSS-REFERENCE

The present application relies on U.S. Patent Provisional ApplicationNo. 63/261,520 filed on Sep. 23, 2021 and entitled “System and Methodfor Viewing Pathology Images”. The '520 application is herebyincorporated by reference.

FIELD

The present specification relates generally to a system and method forfacilitating the storage, retrieval and viewing of large medical images.More particularly the present specification relates to the storage,retrieval and viewing of pathology images.

BACKGROUND

Pathology is a branch of medical science that inquires into the cause,origin, and nature of disease. Pathology involves the examination oftissues, organs, and bodily fluids and also autopsies in order to studyand diagnose disease. Usually a pathologist slices a tissue block intovery thin layers, that are placed on a glass slide and examined under amicroscope. This allows the pathologist to analyze the diseased tissue,generate a diagnosis of the disease or other conditions associated withthat tissue, and author gross or microscopic descriptions of biopsy orcytology specimens.

Pathologists often need to store the original slides for futurereference. However, the specimen storage process is expensive, usuallyrequiring accessibility, cleaning, and protection, which entails greatercare by specialized staff. In contrast, digital storage and distributionmethods reduce these costs, increases the throughput of pathologylaboratories, and enables the sharing of pathology images for analysis.Furthermore, despite using very methodical analytic workflows, it ispossible for the same pathologist to draw different conclusions aboutthe same specimen at different times. Consequently, there is therequirement for enabling second opinions from different pathologistsregarding each sample.

Digital pathology comprises the digital capture of an image from aclassic glass slide as well as management of the associated data. Indigital pathology, glass slides are converted into digital slides thatcan be viewed, managed, shared, and analyzed on a computer, is asub-field of pathology that focuses on data management based oninformation generated from digitized specimen slides. Accordingly, it ispreferred to digitally capture the slide images, store those images, andenable those images to be widely shared. Usually, Digital Slide Scanners(DSS) are used to obtain a digital image of a pathological specimen in awhole-slide images (WSI) format. As the name suggests, these imagescapture the slide as a whole, rather than specific artifacts found bypathologists. The WSI images made by digitized microscope slides atdiagnostic resolution are very large. A typical slide scanned at ×40(approx. 1600 megapixels) produces a file that, even when compressed,requires 2-3 gigabytes of memory and necessitates a viewer applicationwith special functionality to accommodate a pathologist's needs. Since,pathology images are extremely large, wherein each image ranges from 3GB to 5 GB, as compared to radiology images which range from 512 KB to100 MB, there is need for a system and method to enable pathologists tobe able to rapidly access a low resolution version of a pathology imagebut to also be able to then zoom into selected regions of interest inthe image at higher resolutions.

There is also a need to configure pathology slides so that they can bemanaged in systems that use the more common DICOM imaging format. DICOM,or Digital Imaging and Communications in Medicine, is a standard forhandling, storing, printing, and transmitting information in medicalimaging. It includes a file format definition and a networkcommunications protocol. DICOM enables the integration of scanners,servers, workstations, printers, and network hardware from multiplemanufacturers into a picture archiving and communication system (PACS).Different devices come with DICOM conformance statements that identifywhich DICOM classes they support. DICOM has been widely adopted byhospitals and is making inroads in smaller applications like dentists'and doctors' offices. Preferably, pathology images would be madecompatible with PACS in order to enable the easy viewing of largepathology images on web browsers along with providing zooming andpanning functionality.

SUMMARY

The following embodiments and aspects thereof are described andillustrated in conjunction with systems, tools and methods, which aremeant to be exemplary and illustrative, and not limiting in scope. Thepresent application discloses numerous embodiments.

The present specification discloses a system adapted to enable a user toview one or more pathology images in a web browser, wherein the systemcomprises: one or more web servers, wherein the one or more web serversis configured to: obtain at least one of the one or more pathologyimages in a first format; convert the pathology image into a filecomprising images grouped into a plurality of levels, wherein the imagesin different ones of the plurality of levels correspond to a portion ofthe pathology image at a different degree of resolution, wherein eachimage in a given one of the plurality of levels corresponds to a portionof the pathology image at a same degree of resolution, and wherein theimages are in a second format; cause the file to be stored in a firstmemory; convert the images into a third format; and cause the images tobe stored in the third format in a second memory; and a plurality ofprogrammatic instructions adapted to be stored in non-transient memoryand executed on a client device, wherein, when executed, the pluralityof programmatic instructions are adapted to receive a request from theuser to view the pathology image and load one or more of the images fromat least one of the plurality of levels corresponding to a specifiedresolution and wherein the one or more images are in the second format.

Optionally, the file is in a hierarchical representation.

Optionally, the file is in a pyramid representation.

Optionally, the one or more web servers is configured to convert theimages into a third format such that the images' degrees of resolutionare maintained.

Optionally, the plurality of programmatic instructions are adapted toreceive the request identifying the specified resolution.

Optionally, the first memory comprises a web cache in the client device.

Optionally, the second memory comprises a web archive.

Optionally, the first format is a WSI format.

Optionally, the second format is at least one of a TIFF format, a JPEGformat, or a PNG format.

Optionally, the third format is a DICOM format.

Optionally, the file is in a pyramid representation wherein a number ofthe plurality of levels in the pyramid representation file is at leasttwo.

Optionally, the file is in a pyramid representation wherein a number ofthe plurality of levels in the pyramid representation file is no greaterthan one hundred.

Optionally, the file is in a pyramid representation wherein a top of theplurality of levels in the pyramid representation file comprises thepathology image at a lowest resolution.

Optionally, the file is in a pyramid representation wherein a base ofthe plurality of levels in the pyramid representation file comprises thepathology image at a highest resolution.

Optionally, the client device is remote from the one or more webservers.

Optionally, the third format is different from the second format and thefirst format.

Optionally, the second format is different from the third format and thefirst format.

Optionally, each of the first format, second format and third format isdifferent from each other.

Optionally, the plurality of programmatic instructions are adapted toload the one or more images into the web browser.

Optionally, the web browser is coupled with the first memory.

In some embodiments, the present specification discloses a method forviewing pathology images in a web browser, the method comprising:obtaining a pathology image in a first format; converting the pathologyimage into a pyramid representation file comprising images grouped intoa plurality of levels, wherein the images in different ones of theplurality of levels correspond to a portion of the pathology image at adifferent degree of resolution, wherein each image in a given one of theplurality of levels corresponds to a portion of the pathology image at asame degree of resolution, and wherein the images are in a secondformat; storing the pyramid representation file in a first memory;receiving a request from a user to view the pathology image at aspecified resolution; loading one or more images from at least one ofthe plurality of levels corresponding to the specified resolution,wherein the one or more images are in the second format and wherein theone or more images are loaded into a web browser coupled with the firstmemory; converting the images into a third format such that the images'degrees of resolution are maintained; and storing the images in thethird format in a second memory.

Optionally, the first memory comprises a web cache. Optionally, thesecond memory comprises a web archive.

Optionally, the first format is a WSI format. Optionally, the secondformat is at least one of a TIFF format, a JPEG format or a PNG format.Optionally, the third format is a DICOM format.

Optionally, a number of the plurality of levels in the pyramidrepresentation file is at least two. Optionally, a number of theplurality of levels in the pyramid representation file is no greaterthan one hundred. Optionally, a top of the plurality of levels in thepyramid representation file comprises the pathology image at a lowestresolution. Optionally, a base of the plurality of levels in the pyramidrepresentation file comprises the pathology image at a highestresolution.

In some embodiments, the present specification is directed towards asystem adapted to enable users to view pathology images in a webbrowser, the system comprising: one or more web servers, wherein the oneor more web servers is configured to: obtain a pathology image in afirst format; convert the pathology image into a pyramid representationfile comprising images grouped into a plurality of levels, wherein theimages in different ones of the plurality of levels correspond to aportion of the pathology image at a different degree of resolution,wherein each image in a given one of the plurality of levels correspondsto a portion of the pathology image at a same degree of resolution, andwherein the images are in a second format; store the pyramidrepresentation file in a first memory; convert the images into a thirdformat such that the images' degrees of resolution are maintained; andstore the images in the third format in a second memory; and a pluralityof programmatic instructions adapted to be stored in non-transientmemory and executed on a client device remote from the one or more webservers, wherein, when executed, the plurality of programmaticinstructions are adapted to receive a request from a user to view thepathology image at a specified resolution and load one or more imagesfrom at least one of the plurality of levels corresponding to thespecified resolution, wherein the one or more images are in the secondformat and wherein the one or more images are loaded into a web browsercoupled with the first memory.

Optionally, the first memory comprises a web cache. Optionally, thesecond memory comprises a web archive.

Optionally, the first format is a WSI format. Optionally, the secondformat is at least one of a TIFF format, JPEG format, or PNG format.Optionally, the third format is a DICOM format.

Optionally, a number of the plurality of levels in the pyramidrepresentation file is at least two. Optionally, a number of theplurality of levels in the pyramid representation file is no greaterthan one hundred. Optionally, a top of the plurality of levels in thepyramid representation file comprises the pathology image at a lowestresolution. Optionally, a base of the plurality of levels in the pyramidrepresentation file comprises the pathology image at a highestresolution.

The aforementioned and other embodiments of the present specificationshall be described in greater depth in the drawings and detaileddescription provided below.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate various embodiments of systems,methods, and embodiments of various other aspects of the disclosure. Anyperson with ordinary skills in the art will appreciate that theillustrated element boundaries (e.g. boxes, groups of boxes, or othershapes) in the figures represent one example of the boundaries. It maybe that in some examples one element may be designed as multipleelements or that multiple elements may be designed as one element. Insome examples, an element shown as an internal component of one elementmay be implemented as an external component in another and vice versa.Furthermore, elements may not be drawn to scale. Non-limiting andnon-exhaustive descriptions are described with reference to thefollowing drawings. The components in the figures are not necessarily toscale, emphasis instead being placed upon illustrating principles.

FIG. 1 is a block diagram depicting a system for viewing medical images,in accordance with an embodiment of the present specification;

FIG. 2 illustrates a diagram of a pyramid representation of pathologyimages, in accordance with an embodiment of the present specification;

FIG. 3 is a flow diagram illustrating a process of converting pathologyimages to a DICOM format which may be accessed by a web browser forviewing, in accordance with an embodiment of the present specification;

FIG. 4A is a flowchart describing a method of viewing pathology imagesvia a web browser, in accordance with an embodiment of the presentspecification; and

FIG. 4B is a flowchart describing another method of viewing pathologyimages via a web browser, in accordance with an embodiment of thepresent specification.

DETAILED DESCRIPTION

The present specification is directed towards a system and method forviewing both pathology and radiology images in a web browser. Inembodiments, the radiology images are represented in the DICOM standardformat, whereas the pathology images are represented in a plurality ofproprietary formats collectively known as Whole Slide Image (WSI)format. In embodiments, the pathology image representation format isfirst converted to a DICOM format and then stored in the system whichenables viewing of the stored images via a web browser. In embodiments,the pathology images represented in WSI format are first converted intoa pyramid representation format and subsequently converted to a DICOMformat.

The present specification is directed towards multiple embodiments. Thefollowing disclosure is provided in order to enable a person havingordinary skill in the art to practice the invention. Language used inthis specification should not be interpreted as a general disavowal ofany one specific embodiment or used to limit the claims beyond themeaning of the terms used therein. The general principles defined hereinmay be applied to other embodiments and applications without departingfrom the spirit and scope of the invention. Also, the terminology andphraseology used is for the purpose of describing exemplary embodimentsand should not be considered limiting. Thus, the present invention is tobe accorded the widest scope encompassing numerous alternatives,modifications and equivalents consistent with the principles andfeatures disclosed. For purpose of clarity, details relating totechnical material that is known in the technical fields related to theinvention have not been described in detail so as not to unnecessarilyobscure the present invention.

In the description and claims of the application, each of the words“comprise”, “include”, “have”, “contain”, and forms thereof, are notnecessarily limited to members in a list with which the words may beassociated. Thus, they are intended to be equivalent in meaning and beopen-ended in that an item or items following any one of these words isnot meant to be an exhaustive listing of such item or items, or meant tobe limited to only the listed item or items. It should be noted hereinthat any feature or component described in association with a specificembodiment may be used and implemented with any other embodiment unlessclearly indicated otherwise.

It must also be noted that as used herein and in the appended claims,the singular forms “a,” “an,” and “the” include plural references unlessthe context dictates otherwise. Although any systems and methods similaror equivalent to those described herein can be used in the practice ortesting of embodiments of the present disclosure, the preferred, systemsand methods are now described.

As used in this specification, the conventional pathology image formator Whole Slide Image (WSI) format shall refer to each of the followingfile formats (referring to file extensions and their descriptions):.tiff as a single-file pyramidal tiled TIFF or BigTIFF with non-standardmetadata; .sys as single-file pyramidal tiled with non-standard metadataand compression; .tif as single-file pyramidal tiled TIFF, withnon-standard metadata and compression; .vms, .vmu, or .ndpi asmulti-file JPEG/NGR with proprietary metadata and index file formats andsingle-file TIFF-like format with proprietary metadata; .scn as asingle-file pyramidal tiled BigTIFF with non-standard metadata; .syslideas a SQLite database containing pyramid tiles and metadata; .mrxs as amulti-file with proprietary metadata and indexes; and .bif as asingle-file pyramidal tiled BigTIFF with non-standard metadata andoverlaps, or any other file format that complies with a conventionalWhole Slide Image format.

Embodiments of the system of the present specification comprise acombination of web servers, a load balancer server, or a Kubernetesplatform, a web viewer cache server, and a web browser accessible fromone or more computers. The web browser, and thereby the embodiments,take advantage of some of the features of HTML 5, and provide for moreefficient medical imaging viewing. In an embodiment, the web browser ofthe present system is functionally capable of rendering the images witha ‘canvas’ tag introduced in HTML 5 images. In an embodiment, the webserver of the present system functions as a data processor thatpre-processes medical images and stores the results in the web cache,which images may subsequently be transmitted using HTTP.

As used in this specification, the term “web cache” refers to a memorylocation (typically disk space local to a client device) where files,such as images, are stored in a format optimized for a web browser, suchas a JPEG format. The storage is temporary and any such images will bedeleted as needed, such as when a fixed amount of disk space has beenreached and under a predefined rule, such as the first-in, first-outrule.

As used in this specification, the term “web archive” refers to a memorylocation (typically remote from a client device, such as in a cloud ornetwork) where files, such as images, are stored persistently andpreferably in a predefined format, such as a DICOM format. This memorylocation grows as needed and files, such as images, are deleted onlywhen specifically requested by a user.

In embodiments, the system of the present specification provides bothreal time processing and pre-fetch processing of medical images by theweb servers. In that regard, a load balancer server is provided in someembodiments to distribute and manage the work load performed by the oneor more web servers to optimize processing, particularly in situationswhere there are numerous client-side users seeking access to the medicalimages stored in the system of the present specification. In someembodiments, the present specification employs a Kubernetes platform todistribute and manage the work load performed by the one or more webservers to optimize processing. The Kubernetes platform, as is known, isan open-source container orchestration platform that enables theoperation of an elastic web server framework for cloud applications.

FIG. 1 is a block diagram depicting the system for viewing medicalimages, in accordance with an embodiment of the present specification.The system 100 comprises a client side system 10, a server side system60, an image archive 50 coupled with the server side system 60 and ahospital information system (RIS) 40 and/or radiology information system(RIS) 40, and/or lab information system (LIS), also coupled with theserver side system 60. Referring to FIG. 1 , the client-side system 10comprises one or more computers 20 comprising web browsers 22. In anembodiment, the web browsers 22 employ HTML 5 software and a monitor 24for viewing medical images. In embodiments, the computers 20 may becomprised within or outside the HIS 30 or RIS 40 or LIS.

Through the use of computers 20 within or without the HIS 30 or RIS 40,requests for and access to stored images may be made through the use ofserver side system components 60. In some embodiments, the server sidesystem components 60 comprise one or more web servers 70 a, 70 b, a webviewer cache server 80, which may be simply a file server on whichviewer cache capabilities are programmed, and a load balancer server ora Kubernetes platform 90 to distribute and manage the work loadperformed by the one or more web servers 70 a, 70 b, to optimizeprocessing. Connections between the individual components of the systemcomponents 60, and the connections between the computers 20 within orwithout the HIS 30 and RIS 40 or LIS, are made via one or more ofnumerous possible interfaces, such as a private network, a publicnetwork, and/or the Internet. The connection vehicle is not critical tofunctionality of embodiments of the present invention.

In an embodiment, the web browsers 22 load the data directly from theweb viewer cache 80 and display them to the user locally. Hence, inembodiments, the web server (70 a, 70 b) is not involved functionallyfor user display. In embodiments, the web servers are configured to beaccessed by multiple web browsers simultaneously, even when multipleservers are being employed in synchronous operation. In an embodiment,the web viewer cache 80 is also configured to detect the failure of anyserver being employed in data processing, and restart the processingsteps handled by the failed server using another server.

In embodiments, the present system comprises multiple instances of theweb server (70 a and 70 b) which are coordinated by the load balancerserver or the Kubernetes platform 90. The instances of the web servershare the common web viewer cache 80 which stores the result of theprocessing of both the radiology images and pathology images, optimizedfor viewing in the browser 22. The processed images are permanentlystored in the image archive 50 in the DICOM format.

In various embodiments, the system 100 receives pathology images in WSIformats, or a plurality of other non-DICOM formats, and converts saidimages to a DICOM format prior to storing them in the image archive 50.The DICOM format allows storage of metadata regarding correspondingpatients along with the images and is compatible with the picturearchiving and communication system (PACS) enabling images in DICOMformat to be stored and transmitted using commonly used DICOM devices,such as DICOM Archives, DICOM Routers and DICOM Viewers. In embodiments,the pathology images may be represented in a plurality of proprietaryformats, which are collectively known as Whole Slide Image (WSI). Asmentioned earlier, there are multiple file format in this category, suchas but not limited to, .sys, .tif, .tiff, and .bif, among others.

In an embodiment, the system 100 processes the pathology imagesrepresented in the WSI format and converts said images to a pyramidrepresentation, which is commonly used for viewing pathology images in aweb browser, before converting said images to DICOM format. Sinceuncompressed pathology images are large, ranging typically from 3 Gb to5 Gb, and are stored in different proprietary formats (WSI), it isdifficult to view said images on a web browser using conventional means.Radiology images which are much smaller in size are downloaded entirelyon a web browser for viewing. However, due to their large size,pathology images cannot be downloaded on a web browser entirely. Hence,the system of the present specification converts pathology images inproprietary WSI formats to a pyramid representation which enables onlythe portions of a pathology image at predefined resolutions desired tobe viewed, to be downloaded on a web browser. The pyramid representationof pathology images involves organizing the data of a pathology imageinto multiple tiles/levels, wherein each tile/level comprises portionsof the image at a predefined resolution.

FIG. 2 illustrates a diagram of the pyramid representation of pathologyimages. In embodiments, a pathology image in WSI format is converted toa pyramid representation 200, wherein said representation enables saidimage to be stored at multiple levels of zoom or resolution. A base 202of the pyramid 200 comprises a highest resolution representation of thepathology image, while a top 204 comprises a lowest resolutionrepresentation of the pathology image. In embodiments, the lowestresolution image is typically a thumbnail image, which is a verylow-resolution version of the image, enabling a viewer to easily see theentire image. The pyramid representation 200 comprises a plurality oflevels 206, wherein each level comprises the pathology image at anintermediate resolution which can be loaded onto a web browser whenrequired for viewing. In embodiments, the base 200 or the bottom mostlevel of the pyramid representation 200, comprises the image as it wasacquired, meaning at the image's full resolution, while, each levelabove the base 200 comprises the image at half of the resolution in eachdimension (one quarter of the resolution) of the previous level. In anembodiment, the pyramid representation 200 has at least two levels and amaximum of 100 levels.

In various embodiments, the system of the present specification enableseasy viewing of pathology images via a web browser. FIG. 3 illustrates aflow diagram of the process of converting pathology images to the DICOMformat which may be loaded on to a web browser for viewing, inaccordance with an embodiment of the present specification. As shown inFIG. 3 , a pathology image 302 is firstly converted into a pyramidrepresentation 304 and stored in a web cache 306. Next, each level ofthe pyramid representation 304 comprising the image at a specificresolution is converted into an image represented in the DICOM format.

In embodiments, each level of the pyramid representation comprises aplurality of tiles, whereby each tile has pixel dimensions such as, butnot limited to, 256×256, 512×512, or any increment within or from128×128 to 2048×2048. In various embodiments, the tiles are typicallyimages in a graphical format, such as a JPEG format. Since each level ofa pyramid representation comprises different resolution levels of thesame image, each level comprises a different number of tiles. Inembodiments, each level of a pyramid representation is stored in asingle DICOM file, and each tile is represented as a ‘frame’ in theDICOM file. In some embodiments, a DICOM file is a multiframe filestoring multiple images in formats such as, but not limited to JPEGformat. A pathology file converted into a pyramid representation isallotted a predetermined unique identification code known as a StudyUID.All of the images in DICOM files corresponding to the same pyramidrepresentation are tagged with, or otherwise have associated therewith,the same StudyUID. Preferably, however, each level of images in theDICOM files has a different and unique SeriesUID code that isrepresentative of the associated different resolution of the image. Thebottom most level of the pyramid representation comprises the image asit was acquired, meaning at the image's full resolution, while, eachlevel above the bottom level comprises the image at half of theresolution in each dimension (one quarter of the total resolution) ofthe previous level. In an embodiment, when the image resolution at alevel becomes smaller than a predefined value, such as, for example lessthan half of a tile size, a next upper level of the pyramidrepresentation may be generated by downsampling the previous level.

Hence the pyramid representation 304 is converted into a plurality ofDICOM files 308, wherein the number of DICOM files 308 is equal to thenumber of levels in the pyramid representation 304, and each DICOM file308 represents the image 302 at a specific, unique and predeterminedresolution. The DICOM files 308 are stored in an image archive which maybe a cloud based storage 310. A plurality of other images 320 in DICOMformat, such as, but not limited to radiology images, may also be storedin the cloud based image storage 310. When a user 312 requests to viewthe image 302 at a specified resolution, the corresponding image (injpeg format) from a corresponding DICOM file 308 is fetched from thecloud based storage 310 to the web cache 306, from where an accessmodule 322 (such as a load balancer or a Kubernetes platform shown inFIG. 1 ) fetches said image by using the internet HTTPS protocol 324 forviewing by the user 312 in a web browser 314. The conversion, storageand fetching of the pathology image 302 for viewing in the web browseris managed by a cache and process management module 316 running in oneor more web servers of the system of the present specification.

In some embodiments, as shown in FIG. 4A, at step 450, a softwareapplication on a local client device receives a pathology image, from athird party system, in a first format. Thus, a pathology image in aconventional first file format, such as WSI for example, is received bya software application executing in a client device with a browser. Thesoftware application is configured to access and manage a web cachelocal to the client device.

The software application converts, at step 452, the pathology image (inthis case, the pathology image that is in the first file format, WSI)into a pyramid representation defined by a plurality of images in asecond format which is stored in the web cache (which, in an embodiment,is a first memory). In embodiments, the second format may be a TIFF,JPEF, or PNG format, for example. In the software application, at step454, the pyramid representation is converted to one or more image filesin a third format, wherein the third format may be a DICOM format. Thesoftware application transmits, at step 456, the one or more images inthe third format (for example, DICOM format) to a web archive (which, inan embodiment, is a second memory), and then deletes it from the webcache. Thus, the software application causes the file, which is in apyramid representation, to be deleted from the web cache after it hasbeen stored in the web archive in the form of one or more files in athird format (for example, DICOM format).

When the user requests the study corresponding to the pathology image atstep 458, the software application searches the web cache. If, at step460, it is determined that the study is present in the web cache, thesoftware application causes the web browser to display thestudy/pathology image at step 462. If a pathology image/study requestedby a user via the software application is not in the web cache, at step464, the software application will access the web archive and acquirethe corresponding one or more image files in the third format (forexample, DICOM format) into the web cache. At step 466, the acquired oneor more image files in the third format (for example, DICOM format) thatare now in the web cache are converted it to the pyramid representationin the web cache, as described above, for display via the web browser,such as at step 462.

FIG. 4B is a flowchart depicting another method of viewing pathologyimages via a web browser, in accordance with an embodiment of thepresent specification. At step 402 a pathology image file in a WSIformat is converted into a pyramid representation. The pyramidrepresentation comprises a plurality of levels, wherein each levelcomprises the pathology image file stored in a predefined uniqueresolution, and wherein a bottom most level of the pyramid comprisessaid file represented in a highest resolution, the top most level of thepyramid comprises said file represented in a lowest resolution andintermediate levels comprise said file in a plurality of intermediateresolutions arranged in an ascending order from top to bottom level ofthe pyramid representation. In embodiments, one or more web servers ofthe system of the present specification, such as shown in FIG. 1converts the pathology image file in a WSI format into a pyramidrepresentation, by using parameters such as, but not limited to, a sizeand format of each level of the pyramid. In some embodiments, the formatmay be a JPEG format.

At step 404 the pyramid representation of said pathology image is storedin a web cache of the system of the present specification. In anembodiment the web cache is as shown in FIG. 1 . At step 406 each image,which is in a first format and represents a specific, differentresolution level of the pyramid representation, is converted into acorresponding image in a DICOM format. In an embodiment, the firstformat is a WSI format. In other embodiments, the first format may be ofany format type. In some embodiments, the first format may be in a DICOMformat wherein the DICOM format files do not contain all of the levelsof the pyramid; the tile size used in the DICOM files is not optimal forviewing (too large or too small); or the format of the images in theDICOM format files are not optimal for viewing, for example if theformat is an uncompressed format such as, but not limited to, TIFF.Hence, the entire pyramid representation of a single WSI image isconverted to a plurality of DICOM files, wherein each DICOM filecomprises at least one of the pyramid levels of the pathology image thatcorresponds to a specific, predefined, and unique resolution. Inembodiments, one or more web servers of the system of the presentspecification, such as is shown in FIG. 1 converts the pyramidrepresentation into the plurality of DICOM files. Hence, in embodiments,step 406 comprises converting the pathology image into a pyramidrepresentation file comprising a plurality of levels, wherein each ofthe plurality of levels corresponds to the image at a different degreeof resolution, and wherein each level stores the image in a secondformat at a different degree of resolution; and storing the pyramidrepresentation file in a web cache. In various embodiments, the secondformat may be a DICOM image format, such as, but not limited to TIFF,JPEG, and PNG.

At step 408 the plurality of DICOM files are stored in an image archivecomprising other DICOM files representing other images such as pathologyimages and radiology images. In embodiments, the image archive storesimages in the pyramid format and the corresponding DICOM files aredeleted. In embodiments, the image archive comprises pyramid filescomprising multiple levels of DICOM images, wherein each of the pyramidlevels has a predetermined size with a predetermined specific encoding,such as but not limited to TIFF, JPEG, and PNG.

Stated differently, in one embodiment, a pathology image in aconventional file format, such as WSI is received by a softwareapplication executing in a client device with a browser. The softwareapplication is configured to access and manage a web cache local to theclient device. The software application converts the WSI formatted fileinto a pyramid representation with images, as described above, that arein a TIFF, JPEF, or PNG format and which is stored in the web cache. Thesoftware application transmits the file, which is in a pyramidrepresentation, to a web archive. At the web archive or in the softwareapplication (prior to transmission), the pyramid representation isconverted to one or more files in a DICOM format. The softwareapplication causes the file, which is in a pyramid representation, to bedeleted from the web cache after it has been stored in the web archivein the form of one or more files in a DICOM format. If a study requestedby a user via the software application is not in the web cache, thesoftware application will access the web archive, request thecorresponding one or more files in a DICOM format, receive the one ormore files in a DICOM format, and convert it to the pyramidalrepresentation, as described above, for display via the web browser.

At step 410 a request is received from a viewer for viewing a pathologyimage. In embodiments, the received request is for viewing a pathologyimage at a specified resolution. At step 412 it is determined if therequested pathology image is stored in the web cache. At step 414 if therequested pathology image is not stored in the web cache, it isdetermined if the requested pathology image is stored in the imagearchive. If requested pathology image is not stored in the web cache andif the requested pathology image is stored in the image archive, saidimage is fetched to the web cache at step 416. In embodiments, step 416comprises extracting the pyramid levels/tiles, which are stored asframes in JPEG format in the image archive, and storing the extractedimages in the web cache as JPEG images, enabling efficient access tosaid images by the browser. In an embodiment, step 416 comprises loadingthe image in the second format (for example, TIFF, JPEG, and PNG)corresponding to the specified resolution onto a web browser that is indata communication with the web cache.

In embodiments, a load balancer server or a Kubernetes platform and oneor more web servers, as shown in FIG. 1 enables fetching the requestedpathology image from the web cache or the image archive. If therequested pathology image is not stored in the image archive or the webcache, then the requested pathology image file in a WSI format isconverted into a pyramid representation at step 402 and steps 402 to 416are carried out. At step 418 the fetched image is loaded onto a webbrowser for viewing by the user.

In an embodiment, the web cache has a maximum size, and once it exceedsthat capacity, a clean-up process would preferably automatically analyzeall the data in the Web Cache and remove some of it. At any imageviewing request received by the web browser the list of DICOM imagesprocessed and available on the web cache is sent to the web browser viathe load balancer or the Kubernetes platform, and/or one or more webservers, as shown in FIG. 1 . The web server(s) indicates to the webbrowser if the processing is completed or not. In a case where theprocessing of the requested pathology image is not complete, the webbrowser will typically re-request the image information in few secondsuntil it receives the indication that the processing is complete and theimage is available for viewing in the web browser.

In various embodiments, the method of the present specification allowsimage data in WSI format to be converted in a web cache so that theimage is immediately available to a user for viewing. Since, the webcache has a limited memory, the pathology images converted to DICOMformat are stored in an image archive for long term storage, so thateven the images evicted from the web cache may be retrieved from theimage archive to the web cache and be made available for viewing in aweb browser.

The above examples are merely illustrative of the many applications ofthe system and method of the present specification. Although only a fewembodiments of the present invention have been described herein, itshould be understood that the present invention might be embodied inmany other specific forms without departing from the spirit or scope ofthe invention. Therefore, the present examples and embodiments are to beconsidered as illustrative and not restrictive, and the invention may bemodified within the scope of the appended claims.

What is claimed is:
 1. A system adapted to enable a user to view one ormore pathology images in a web browser, wherein the system comprises:one or more web servers, wherein the one or more web servers isconfigured to: obtain at least one of the one or more pathology imagesin a first format; convert the pathology image into a file comprisingimages grouped into a plurality of levels, wherein the images indifferent ones of the plurality of levels correspond to a portion of thepathology image at a different degree of resolution, wherein each imagein a given one of the plurality of levels corresponds to a portion ofthe pathology image at a same degree of resolution, and wherein theimages are in a second format; cause the file to be stored in a firstmemory; convert the images into a third format; and cause the images tobe stored in the third format in a second memory, wherein the thirdformat is different from the second format and the first format; and aplurality of programmatic instructions adapted to be stored innon-transient memory and executed on a client device, wherein, whenexecuted, the plurality of programmatic instructions are adapted toreceive a request from the user to view the pathology image and load oneor more of the images from at least one of the plurality of levelscorresponding to a specified resolution and wherein the one or moreimages are in the second format.
 2. The system of claim 1, wherein thefile is in a hierarchical representation.
 3. The system of claim 1,wherein the file is in a pyramid representation.
 4. The system of claim1, wherein the one or more web servers is configured to convert theimages into a third format such that the images' degrees of resolutionare maintained.
 5. The system of claim 1, wherein the plurality ofprogrammatic instructions are adapted to receive the request identifyingthe specified resolution.
 6. The system of claim 1, wherein the firstmemory comprises a web cache in the client device.
 7. The system ofclaim 1, wherein the second memory comprises a web archive.
 8. Thesystem of claim 1, wherein the first format is a WSI format.
 9. Thesystem of claim 1, wherein the second format is at least one of a TIFFformat, a JPEG format, or a PNG format.
 10. The system of claim 1,wherein the third format is a DICOM format.
 11. The system of claim 1,wherein the file is in a pyramid representation and wherein a number ofthe plurality of levels in the pyramid representation file is at leasttwo.
 12. The system of claim 1, wherein the file is in a pyramidrepresentation and wherein a number of the plurality of levels in thepyramid representation file is no greater than one hundred.
 13. Thesystem of claim 1, wherein the file is in a pyramid representation andwherein a top of the plurality of levels in the pyramid representationfile comprises the pathology image at a lowest resolution.
 14. Thesystem of claim 1, wherein the file is in a pyramid representation andwherein a base of the plurality of levels in the pyramid representationfile comprises the pathology image at a highest resolution.
 15. Thesystem of claim 1, wherein the client device is remote from the one ormore web servers.
 16. The system of claim 1, wherein the plurality ofprogrammatic instructions are adapted to load the one or more imagesinto the web browser.
 17. The system of claim 1, wherein the web browseris coupled with the first memory.
 18. A system adapted to enable a userto view one or more pathology images in a web browser, wherein thesystem comprises: one or more web servers, wherein the one or more webservers is configured to: obtain at least one of the one or morepathology images in a first format; convert the pathology image into afile comprising images grouped into a plurality of levels, wherein theimages in different ones of the plurality of levels correspond to aportion of the pathology image at a different degree of resolution,wherein each image in a given one of the plurality of levels correspondsto a portion of the pathology image at a same degree of resolution, andwherein the images are in a second format; cause the file to be storedin a first memory; convert the images into a third format; and cause theimages to be stored in the third format in a second memory, wherein eachof the first format, second format and third format is different fromeach other; and a plurality of programmatic instructions adapted to bestored in non-transient memory and executed on a client device, wherein,when executed, the plurality of programmatic instructions are adapted toreceive a request from the user to view the pathology image and load oneor more of the images from at least one of the plurality of levelscorresponding to a specified resolution and wherein the one or moreimages are in the second format.
 19. The system of claim 18, wherein thefile is in at least one of a hierarchical representation or a pyramidrepresentation.
 20. The system of claim 18, wherein the one or more webservers is configured to convert the images into a third format suchthat the images' degrees of resolution are maintained.
 21. The system ofclaim 18, wherein the plurality of programmatic instructions are adaptedto receive the request identifying the specified resolution.
 22. Thesystem of claim 18, wherein the first memory comprises a web cache inthe client device.
 23. The system of claim 18, wherein the second memorycomprises a web archive.
 24. The system of claim 18, wherein the firstformat is a WSI format.
 25. The system of claim 24, wherein the secondformat is at least one of a TIFF format, a JPEG format, or a PNG format.26. The system of claim 25, wherein the third format is a DICOM format.27. The system of claim 18, wherein the file is in a pyramidrepresentation and wherein a number of the plurality of levels in thepyramid representation file is at least two.
 28. The system of claim 18,wherein the file is in a pyramid representation and wherein a number ofthe plurality of levels in the pyramid representation file is no greaterthan one hundred.
 29. The system of claim 18, wherein the file is in apyramid representation and wherein a top of the plurality of levels inthe pyramid representation file comprises the pathology image at alowest resolution.
 30. The system of claim 18, wherein the file is in apyramid representation and wherein a base of the plurality of levels inthe pyramid representation file comprises the pathology image at ahighest resolution.